5 Physical Details That Reveal Highly Personal Information

#2. You Can Find Out What Sports You'll Be Good at With a Few Body Measurements

Obviously, you can look at a big fat guy and tell that he's going to have a biological advantage at sumo wrestling, or at a dangerously underweight preteen girl and know that you probably shouldn't challenge her to a friendly round of uneven bars. But it's not so easy when it comes to regular sports, like swimming or running or lacrossing. Except, that is, if you know what to look for.

The position of your belly button can help determine whether you will be better at running or swimming. No word on how it affects lacrossing, but we're pretty sure lacrosse was invented for Tommy Hilfiger ads in the '90s, so the point is moot now.

The first thing most of us notice about a navel is whether it's normal (an innie) or tragically deformed (an outie). Beyond that, who cares? What are we, I Dream of Jeannie censors? It turns out the direction of the belly button matters a whole lot less than its location on the belly. Because that dirty, bacteria-generating chasm we call the navel is actually the body's center of gravity.

This is important, because a higher center of gravity gives you a competitive edge in running, while a lower one helps when it comes to swimming. According to one researcher, "Locomotion is essentially a continual process of falling forward, and mass that falls from a higher altitude, falls faster." So when we see West African runners mop up the international track floor, it's not a sketchy, racially charged theory that's helping them succeed. What we're seeing is a hidden height advantage provided by belly buttons that are 1.18 inches higher than those of their white competitors.

And when we notice that there aren't as many elite black swimmers, it's because that lower center of gravity gives whites longer torsos, which means they can generate a larger wave, which makes them faster in the water. As for Asians, they have the same belly button proportions as whites, but they're also shorter, so they enter the pool with a distinct height disadvantage.

Photos.comPlus, those hats have wicked drag.

#1. You Can Find Out How Virile a Man Is by Measuring His, Uh ...

If you could know ahead of time whether or not your potential husband was a one-man stud farm or loaded up with a bunch of jizz duds, would you want to know? What if we told you the way to find out involved measuring a little patch of male anatomy best left to the crotch of his drawers?

Think about this, ladies. The man who will father your future children could be sitting beside you right now. All you have to do is strip him naked, squat down, lift up his scrotum and ask him to spread his legs. Wait, maybe it would just be easier if he does a naked handstand and you grab his ankles and -- wait, maybe we should explain what we're talking about.

Photos.com"It's not working. Lay down and spread 'em!"

How? Tell Me!

Measure his taint. The shorter the junk, the weaker the spunk. If the perineum is longer, his sperm is stronger. You should get that sewn onto a pillow.

We know this because researchers have gotten down on their knees and run their tape measures where the sun don't shine. Real researchers, men and women with years of education under their belts, had to make their way to the dark side of the ball sack, lift the junk out of the way, place a tape measure at the dude's asshole and start counting. Twice. Once from the underside of the scrotum to the anus, and once from the top of the penis stem to the anus.

Photos.com"And I'd do it again, too."

So what is a normal taint length? About 2.04 inches, or a lady-thumb long. Any measurement below this and your splooge might end up "in the subfertile range." Or, in medical terms, men who have a shorter taint have "lower sperm counts, poorer quality sperm, lower sperm concentrations and lower motility." The reason for the connection might have to do with prenatal exposure to a class of chemicals called phthalates, which have been shown to affect testosterone exposure. So the guys with shorter grundles got a whiff of some bad stuff in utero, and their man parts will pay for it for the rest of their lives.

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